The use of allograft bone particles to fill defects or cavity repair in bone is well understood in the art. Its use has had varying amounts of success dependent on how the bone particles were cleaned, prepared, processed and sized.
Conventional wisdom believed new bone growth would be facilitated by increasing the surface of the bone. That led to a false belief that bone crushed into a fine powder of less than a micron would be best. In practice, this simply was not the case. The powder when packed into the defect had no void spaces to facilitate new ingrowth.
In U.S. Pat. No. 7,335,381; it was determined that an array of several different particle sizes would help induce new bone growth if the bone was properly cleaned and prepared into particles in a grinding procedure wherein the bone never is heated at or above 40 degrees C. as a result of the grinding.
If the bone was non-demineralized and frozen or freeze dried then the osteoinductive properties would not be degraded and a loss of osteoinductive activity could be avoided.
The result was a superior bone particle mixture. The use of this particle mixture 30 has been successful. Synthetic bone graft material is being used, but these materials simply cannot duplicate the porosity and ability to be resorbable when compared to natural cellular materials.
The application of the bone particle mixture during a bone defect repair is not ideal. Dry application of the bone mixture while not difficult can be messy with some particles spilling out of the defect cavity. Ideally, the bone mixture should be delivered with no spillage and wasted material. The dense packing of the microparticles by themselves admixed with saline or blood prevents flow through a small aperture (12 mm or less).
In most less invasive procedures, the surgical repair may only be visible using x ray or other imaging devices and also requires cannulas less than 8 mm. Even if flow could be achieved, a concern of over filling or under filling the cavity is greatly increased.
It is an objective of the present invention to provide a non-synthetic bone defect repair composition that accelerates bone growth and can be delivered in a more accurate convenient manner allowing the surgeon to see the material as it is being delivered to the implant or bone defect being repaired.